


Watch Out for Conveyor Belts

by knave_of_swords



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Modern Setting, Begging, Creampie, Dom/sub, F/M, Kink Meme, Multiple Orgasms, Overstimulation, Smut, Step-Sibling Incest, Vaginal Sex
Language: English
Status: Completed
Published: 2020-05-27
Updated: 2020-05-27
Packaged: 2021-03-03 04:54:23
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,185
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24399085
Author URL: https://archiveofourown.org/users/knave_of_swords/pseuds/knave_of_swords
Summary: Dimitri is ridiculously in love with Edelgard, who by unfortunate circumstance, is his step-sister. When their parents take a week-long romantic getaway vacation one summer, it takes Edelgard four days and quite a lot of unsubtle seduction to finally rile Dimitri up enough to actually fuck her.
Relationships: Dimitri Alexandre Blaiddyd/Edelgard von Hresvelg
Comments: 10
Kudos: 126
Collections: FE3H Kink Meme





	Watch Out for Conveyor Belts

**Author's Note:**

> kink meme prompt:
> 
> https://3houseskinkmeme.dreamwidth.org/476.html?thread=197852

It's the fourth night that their parents have been gone on their week-long romantic getaway, and Dimitri is pretty sure that he's going to end up spontaneously combusting before they get back. He and Edelgard have the house to themselves, which wouldn't normally be an issue. Except that because Ingrid and Sylvain were at some summer training lacrosse camp, and Felix was screening his calls, Dimitri had nowhere to go during the day. This wouldn't appear to be much of an issue either, if not for Edelgard's propensity to wear the shortest shorts that barely covered her ass and tank tops without a bra underneath. That too, shouldn't be an issue, either, Dimitri knows. He can only blame his current condition on his own absurd, depraved lust for his step-sister. 

"Dima? You there?" Dimitri snaps back to reality and sees Edelgard leaning forward across the dinner table, waving her hand in his face. He studiously avoids looking down her shirt at her bare breasts, despite her cleavage being in the middle of his line of sight. He instead tries to look Edelgard in the eye.

"Oh yes, I'm fine," he tells her.

"Okay. Anyways, I thought we could watch a movie tonight. What do you think?" What does he think? Dimitri groans internally. He loves spending time with her, he really does. He's attracted to her, but it's not just a sexual thing for him. It would be easier for him if it were, since the obvious solution would be to just go out and get laid until he stops thinking perverted thoughts about his sister. But he finds himself dreaming of romantic fantasies with Edelgard just as often as his mind wanders towards sexual deviancy regarding her. So really, he does want to watch a movie with her. It doesn't matter what movie. 

On the other hand, he's certain to actually explode if he lets himself lounge with her on the couch as they watch the movie, her legs casually tangling with his. He's still stuck alone with her for three more nights, and he already feels at his breaking point. It's ridiculous how often his mind goes straight to the gutter around her. He's honestly shocked that he's made it through dinner without popping a boner. Dimitri realizes that he's zoned out again, and that Edelgard is looking at him expectantly. He clears his throat.

"A movie sounds fine," he tells her, against his better judgement. "Anything in particular you have in mind?" Edelgard puts her hand to her chin, thinking.

"I've been wanting to rewatch _The Cabinet of Dr. Caligari_ lately," she admits. It takes Dimitri a moment to parse his memory and remember which movie she's referring to.

"Oh. The black and white German one?" he asks. Even if it isn't the one he's thinking of, Dimitri is nearly certain that it fits that description anyways. He's sat through more old German expressionist films with Edelgard than he thought even existed in the world to begin with. She loves the genre, and even though Dimitri has no clue what makes it so appealing to her, he can't ever tell her no when she asks if he wants to watch with her. 

"Yeah," Edelgard answers, lighting up. "It's one of the silent ones. Directed by Robert Wiene, though, not Fritz Lang." Dimitri internally groans, though he fixes a smile on his face outwardly as he nods his head as Edelgard starts talking about color symbolism in the movie. Silent films are the worst of the movies he watches with Edelgard. But she looks so delighted that he's willing to watch it with her, so Dimitri resigns himself to his fate for the evening. At least she hadn't asked him to watch _Metropolis_ with her again. He isn't sure he can sit through two and a half hours of silent German expressionist cinema again, even for Edelgard. 

* * *

Normally when they watch movies together, they sit on opposite ends of the couch with their feet facing each other. This time, though, Edelgard sits in the middle of the couch facing outwards, leaving Dimitri no choice but to sit next to her. Edelgard starts the film, and settles in next to him. Dimitri can barely focus on the television with her next to him like she is. She leans against his shoulder, and he can feel her breasts against his arm. He remembers that she still isn't wearing a bra, and curses his degeneracy. Her hair smells nice, he realizes as she leans closer towards him. Her shampoo must be vanilla-scented.

Dimitri is so distracted by making sure to stay perfectly still as Edelgard snuggles against him, he almost doesn't realize that he's gotten an erection. _Fuck._ He always has the worst luck. Dimitri sneaks a glance towards Edelgard, and is relieved to see that she's focused on the film. She glances back towards him, though, and he realizes that he's been caught staring. He shakes his head to indicate it was nothing important, and leans back onto the couch, trying to find a way to shift his sitting position to obscure his boner. He thinks he's successful when he sits at an angle to Edelgard, but things take a turn for the absolute worst when she leans back and reclines against him. Dimitri freezes, certain that she's going to notice his untimely erection.

But she doesn't say anything, and Dimitri wonders if the blankets casually draped over his lap are hiding his boner despite her practically sitting on top of him. Dimitri can hardly focus on anything but the feel of her ass against him. After a few minutes, he tries to subtly shift away, but Edelgard shifts with him. Dimitri grits his teeth and closes his eyes. He tries to do a breathing exercise that he had read helped with getting rid of unwanted erections, but with Edelgard pressed so close against him, it doesn't work. 

Dimitri finally feels himself snap. "Are you _trying_ to do that?" he asks her, the question coming out more heated than he intends. Edelgard turns towards him with a confused look on her face.

"Do what?" she asks? Dimitri grits his teeth again.

"You're sitting on my lap," he says. 

"You don't like it?" Edelgard seems surprised. "I used to always sit on your lap, Dima."

 _Yeah. When we were kids,_ he thinks. "No," is all he says out loud.

"Really?" Edelgard asks, and he can hear a mischievous undercurrent to her tone. "Then what's this?" she asks, grinding against his cock. Dimitri feels like his mind slams the breaks. She had noticed after all. He wants to die.

"I don't know what you're talking about," he manages to cough out. He picks Edelgard up off of his lap and sets her down next to him, and moves to stand up. Before he can, though, Edelgard places her hand over the bulge swelling out of his sweatpants. He freezes. His cock is throbbing, and he feels heat pulse through his body. Edelgard leans closer towards him.

"I think you do, Dima," she whispers. This is it. Dimitri has had enough. He can't take this anymore. He grabs Edelgard's shoulders and roughly yanks her towards him and kisses her. He feels her momentary shock in the stiffness of her lips, but it quickly goes away as she hungrily kisses him back. Soon, it's actually a bit difficult to kiss her because of how wide she's smiling. He pulls away, annoyed. Edelgard's cheeks are flushed, and there's a smug glint in her eyes as she grins at him. Dimitri realizes that she had planned all of this, had goaded him into this. As much as he's glad to kiss her, finally, he also feels irritated at how she's the one maintaining so much control in this situation. He's determined to unbalance her as much as she had unbalanced him tonight.

He kisses her again, turning her around so she's against the back of the couch. His hands slip underneath the hem of her sweatpants, his fingers pressing into her soft skin. Edelgard lets out a small moan and squirms underneath him, trying to get his hands further down her hips. Dimitri realizes that she isn't wearing any panties, and suddenly his entire body feels too hot, the clothes he's wearing feeling heavy against his skin. He breaks their kiss to pull off his shirt, and then slides his hands back down underneath her sweatpants. Edelgard's eyes wander up and down his chest, one of her hands resting on his left pec.

"God, I wish I could titfuck you," she groans, leaning into his chest to put her face against his chest muscles. She moans as he squeezes her ass, her breath hot against his skin. Dimitri pulls his hands out of her pants, and Edelgard lets out a small whine before she realizes that he only did so to pull her sweatpants off. She shifts to try and help him pull them off of her. He tosses them to the ground to his side, not caring where they ended up. It only mattered that she wasn't wearing them anymore. Edelgard starts to pull her shirt off, and Dimitri helps her pull it over head.

Finally, she's completely unclothed. His cock is aching to be touched. Yet he wants to take a moment, just to look at her, before he goes further. She's so pretty, flushed and naked underneath him. The gentle swell of her breasts barely visible in the half-light coming from the forgotten television behind them. The way a strand of her dark hair is sticking to her forehead with sweat. How she's pressing her thighs together and biting her lip as she fixes her gaze on him. Everything about her makes his heart burst with desire.

"You're beautiful," he mumbles, not realizing that he had spoken aloud until Edelgard replies.

"You're not so bad yourself," she teases back to him, sliding her hand from his pec down to his abs, hovering just above the waistline of his sweatpants. God. He had to touch her again before he exploded. He bends down towards her to kiss and suck at her neck, relishing the gasps he was able to draw out of her by doing so. Dimitri slides his hands back to her ass and down the backs of her thighs, pulling apart her legs slightly. Edelgard whimpers when the pressure of her thighs rubbing against each other stops, but Dimitri feels a sadistic streak of pleasure in denying her that small relief momentarily. He drops his mouth from her shoulder to her breasts, causing Edelgard to arch her back, pressing her chest closer to him. He lazily licks at one of her nipples, and then sucks. The moan that comes out of Edelgard as a result makes his cock throb against her. Dimitri wants her to beg, but he also has his own needs to consider. He grinds against her cunt as he continues to lavish attention on her breasts. Eventually, it’s too much for even Edelgard to keep herself from admitting she needs more.

“Dimitri...” she whimpers. “Ah, please,” she gasps against him.

“Please what?” he growls, releasing her nipple from his mouth. The look Edelgard gives him was likely intended to be annoyed, but it just comes out as desperate.

“Just fuck me already, please,” she begs him, wrapping her legs around his body. “Dimitri, I need you inside me.” Fuck, she knows how to play him, even when she’s desperately begging for him to touch her. He can’t deny her when she tells him things like that, that she *needs* him.

Dimitri pulls his sweatpants down, not even bothering to shake them off of his ankles. His cock springs free, precum dripping all over the head of it. He hesitates for a moment as he positions himself to enter her.

“You’re on birth control, right?” he asks hesitantly.

“IUD,” she answers immediately, and that’s enough for Dimitri to finally push himself inside of her. He can’t help but let out a moan as he enters her, overcome by how good her pussy feels.

“God Dimitri, you’re so big,” Edelgard gasps, her hips squirming underneath him as she adjusts to the feel of his cock.

“Is it too much?” he asks, suddenly concerned. He hadn’t thought about their size difference. Edelgard quickly shuts those worries down, though.

“Fuck no,” she says as she pulls his body closer towards her with her legs. “I don’t think I’ll ever get enough of you.” Dimitri feels his entire body burn with heat as he starts to thrust in and out of her. He bites the inside of his cheek so hard that he tastes copper. He couldn’t cum too early, not before he makes sure that Edelgard knows that she’s not the one in control of this encounter anymore.

Dimitri realizes that Edelgard’s hands had moved down to rub her clit as he thrust inside of her. She lets out a whine when he grabs her hands and pulls them up, pinning her against the couch cushions.

“You cum when I say so,” he gasps. He can hardly see the expression on Edelgard’s face. He wonder if she’s pissed at him for stopping her like that. He almost pauses and asks if she’s alright, but then she’s moaning and shuddering against him, her muscles clenching and then relaxing. He stops moving, incredulous.

“Did you just—“ he starts to ask, but Edelgard interrupts him.

“Yes,” she admits. She turns her head sideways, choosing to look away from him for the first time that night that Dimitri could remember. A slow grin starts to break out on Dimitri’s face. He slowly starts thrusting his hips in and out of her again.

“That horny huh?” he taunts. Edelgard ducks her chin, still looking away from him. He moves one of his hands away from pinning her against the couch, and brushes her clit. She gasps at the light touch, finally turning towards him again.

“Oh God, Dimitri,” she whines desperately, maybe realizing what he’s intending.

“I didn’t say you could cum yet, but you did,” he says as he starts to rub steady circles against her clit. He can feel her twitch violently at his touch, but she only moans and doesn’t tell him to stop. “So this time, only cum when I tell you to.” Edelgard doesn’t reply, too busy gasping and moaning and squirming beneath him as he rubbed her overstimulated clit. The sounds she’s making make his cock throb, desperate for release.

“Dimitri, please,” Edelgard manages to beg between her incoherent groans. Dimitri wants to oblige her so badly. But he can’t reist the urge to draw this out, forcing her to concede to him.

“Beg again,” he commands her, and then grits his teeth to keep himself from spilling over.

“Fuck, Dimitri, please,” Edelgard babbles. She doesn’t stop talking, begging him in a stream of almost nonsensical words. The corners of her eyes glint in the darkness and Dimitri realizes that there are tears in the corners of her eyes. That’s enough for him, he realizes. They both know that he is the one completely in control right now.

“Cum for me then, El,” he finally tells her, and Edelgard cries out as she does just that, for the second time that night. Her eyes are screwed shut and she arches her back as she rides out the waves of her climax. Dimitri feels his legs start to buckle as she relaxes against him. He’s so close. He moves his hands to her hips to help him move in and out of her. He’s gripping her skin so hard he suspects she’ll have bruises in the shape of his fingerprints there tomorrow, but he can’t make himself hold back.

“Ah, Dima,” Edelgard moans softly, and that’s what finally makes him climax, his cum spilling inside of Edelgard. He’s slowing down his thrusts, still wanting stimulation to draw out his orgasm but also wanting to bury his cock as far inside of her as possible.

Somehow, Edelgard is coming again too, for the third time, and that realization sends spikes of heat throughout his body. Finally, he feels his orgasm die down, and he half-collapses on top of Edelgard. They’re both sweaty and hot, and she seems only half conscious after that many hard orgasms in a row. Dimitri smirks, but soon his haze of lust is replaced by post-orgasm clarity.

 _Oh god_ , he realizes with growing horror. _I just fucked Edelgard. My step sister._ He pulls out of her, his cock now soft. The sight of his semen dripping out of her pussy is shamefully arousing. He sits next to her on the couch so he doesn’t have to look at her, and puts his head in his hands. He doesn’t know what he’s going to do now. Edelgard finally stirs next to him, seemingly recovered from her blissed-out haze.

“Dima?” The use of his nickname makes Dimitri groan in shame. “Are you alright?” Edelgard asks, and he can feel her place her soft hand carefully against his shoulder.

“We just had sex,” he groans, dragging his hands down his cheeks as he looks up towards her.

“Yeah, and it was the best sex I’ve ever had,” Edelgard replies like there’s nothing wrong with this whole situation.

“We’re— we’re siblings, El.” He sees Edelgard roll her eyes. “I’m never going to be able to look Dad in the face again,” he continues to moan.

“Dimitri, we’ve both wanted this since God knows how long.” Dimitri turns his face away from her, but he can feel Edelgard scoot up next to him, her bare breasts brushing his arm. She leans into him. “We were never going to have a normal sibling relationship.”

Dimitri turns to look at her again, opening his mouth to argue with her again, but Edelgard catches him in a kiss before he can get any words out. Despite himself, he can’t help but return the kiss eagerly, relishing the feel of her lips against his.

“See?” Edelgard says when they break apart. Dimitri isn’t sure exactly what that kiss had proved, but he feels himself starting to resign himself to this— whatever it was— with Edelgard. “Now shut up and fuck me again,” Edelgard says, starting to regain the air of authority and control she had had earlier that evening. “I want you to come inside me in every room in this house, and we only have a few days before Mom and Dad get back home.” God. Dimitri should know better. He should stand up and reject her. Once was already bad enough. Instead, he finds himself kissing her again, pulling her onto his lap, his cock already starting to stiffen again in anticipation of a second round.

* * *

(They do end up managing to successfully fuck in every room in the house before their parents come home. Dimitri’s best orgasm is when Edelgard blows him in their parents’ bedroom. Edelgard’s favorite is when Dimitri bends her over the kitchen counter and fucks her senseless.)

**Author's Note:**

> getting back in the dimigard groove so I can tell myself if I made any mistakes writing them again I can get them out in this oneshot instead of in my multichap. though I'm really pleased with how this turned out, so I don't even need to tell myself that.


End file.
